How I Met My Great Great Great Grandmother
by Mailani4ewa
Summary: This is my take on how Ms. Tessa Gray meets the inhabitants of the New York Institute. One-shot


**All of these characters belong to the wonderful Cassandra Clare.**

 **Sorry for any editing errors**

 ***This takes place after CoHF and Simon did not loose his memories when he got his immortality taken away. Also Tessa could still read minds after the heavenly fire.**

 ***EDITED AS OF 8/23/16 I WAS READING THROUGH THIS STORY AND THE AMOUNT OF REVISIONS NEEDED BUGGED ME, SO NOTHING ABOUT THE STORYLINE CHANGED***

Jace was getting tired of Magnus being in the institute day in and day out. Don't get him wrong though, Magnus was a great person if not a little too sparkly, but ever since him and Alec got back together they decided to hang out at the institute instead of his place which meant that he was there almost 24/7.

"JACE!" Shouted a voice from the entrance of the institute that was unmistakably Magnus'.

"WHAT DO YOU WANT YOU BLASTED WARLOCK!" Jace replied annoyed. He could never just have peace and quiet now that Magnus was hanging out in the institute, with Izzy yelling at him to rate her outfit and Magnus yelling his name just to annoy him.

"JACE! GET YOUR LAZY ARSE DOWN HERE!" This time it was not Magnus' voice but Clary's. Jace's mood instantly lightened.

Smiling he replied "OK, Miss Fairchild." Racing down to the entrance of the institute in anticipation seeing Clary for the first time in three whole days. He had greatly missed her in the three days of absence and when got down to the entrance he incased her with a hug and a loving kiss. They stayed like that for what felt like centuries and were broken up by Alex coughing.

Jace scowled at Alec and Magnus immediately said "Don't scowl at Alexander, Mr. Herondale." Jace scowled at Magnus, "And don't go scowling at me, honey because that is just a bad first impression to make."

Confused Jace looked around and noticed a fairly tall, pretty girl with grey eyes in the corner watching them with an amused look on her face. She had a simple white blouse on and black leggings. " Ummm... Magnus, who is that?" Jace asked.

Smiling Magnus replied "Introductions will be made later when Izzy and Seamen get here... Which should be any second now."

Jace looked at Clary who waved at the girl who waved back. "Clary, do you know her?"

Clary looked back at Jace "Yeah I've had a brief -"

The institute's doors banged opened "WE'RE HERE, MAGNUS WHAT WAS THIS URGENT BUSINESS YOU WANTED TO TALK..." Izzy stopped yelling and said , "Oh, you're all right here."

"Yes we are. Gosh Isabelle, I think you scared dear Sarah away." Magnus snickered.

Simon burst into the room aggravated and saying "For the last time my name is Simon."

"Whatever. Anyway you are gathered here today to meet a very special person, let's go to the library and introduce each other there."

\- line break to library-

Arriving in the library everyone sat down in a circle. All heads then turned to Magnus who cleared his throat as if he was about to give a speech. "Now, we are here today to meet very special person and I will now let her introduce herself."

The girl with grey eyes smiled. "Before I introduce myself it is my deepest wish that you guys introduce yourselves first." Jace instantly got old vibe from her by the way spoke and the way she held herself, but that old vibe was also mixed with a modern vibe.

She looked at them as if expecting something, then Simon said "Umm... My name is Simon Lewis and I'm ascending soon" the girl nodded.

"Nice to meet you Simon."

"I'm Isabelle Lightwood, call be Izzy" supplied Izzy.

"Pleasure to meet you"

"Alec Lightwood, Magnus' boyfriend." Alec stated proudly.

The girl smiled "Magnus, what happened to all Lightwood look the same."

Magnus blushed "That was a long time ago."

Jace snorted "Well Magnus I hope you don't get Alec and Izzy mixed up because Izzy is clearly a girl. By the way, I'm Jace Herondale boyfriend of the gorgeous redhead next to me." Jace was not sure if it was his imagination, but the girls eyes seemed to soften at his name. "Don't stare please. I know I'm handsome but I'm taken." Jace pulled Clary to close. The girl smiled as if remembering a fond memory.

"I'm Clary Fray and you already know me." The girl smiled.

"Well you guys have all introduce yourself so it is only right if I do the same. I am Tessa Gray and for lack of better words I am a warlock. It's a honor to meet you all." Tessa introduced herself.

Jace found it odd that she said for lack of better words. He was about to ask about it when Izzy beat him to it , "For lack of better words? What dose that mean? Where is your warlock's mark? I don't see one."

Alec gave Izzy a hard look, "Izzy, mind your manners."

Izzy shrugged, "I was only curious." She defended

"Oh, it's quite alright, I would be happy to explain. I unlike the other warlocks have no mark since I am not like the other warlocks, for I have shadowhunter blood and demon blood running through my veins"

Jace thought he heard wrong because there can't be both shadowhunter and demon blood running through someones vains naturally. There was the case of Sebastian, but it was done through experiments. Simon spoke up "I thought it was impossible for a shadowhunter and a demon to create an offspring, the result is stillborn."

"Yes, and many people point that out, but it is possible for that to happen because it is not the shadowhunter blood itself that doesn't allow the baby to be conceived, but the runes that shadowhunters bear on their skin that prevents offsprings. My mother did not know she was a shadowhunter, therefore did not have any marks and mated with a demon that was disguised as my father and created me. I am able to use magic but have no warlock's mark. I also can get pregnant."

Jace took that information in and to clarify he asked "So is that why you are so important to meet? But I don't get why we had to meet you."

"Well Jace Herondale, I used to be very close to shadowhunters."

"And I still don't get why this is important"

"My history with shadowhunters was a story of Carstairs', Branwell's/Fairchild's," Tessa looked at Clary.

"How do you know that Clary is a Fairchild?"

"That is because I have had the pleasure of conversing with her before. If I may continue it was a story of Carstairs', Branwell's/ Fairchild's, Lightwor- excuse me, Lightwood's," she looked at Izzy and Alec in turn, "Lovelace's, though I think the name died during my time with shadowhunters,"

Jace thought that Lovelace sounded familiar, then he remembered that a girl named Jessamine Lovelace had died a traitor to the London enclave, she was the last Lovelace known to the Shadowhunters so the bloodline died.

"and most importantly, a story of Herondale's" Tessa finished looking at Jace. "To be specific the shadowhunters were James or Jem Carstairs, Jessamine Lovelace," Jace knew it! Jessamine Lovelace. "Charlotte Fairchild and Henry Branwell, Gabriel and Gideon Lightwood, and Cecily and William or Will Herondale."

Alec perked up at the mention of Will Herondale and inquired "Magnus, is that the same Will that Camille talked about?"

Magnus looked at Alec before replied "Yes my dear Alexander"

Now it was Tessa's turn to ask a question, "Why would Camille speak of Will?"

Magnus sighed and said "Camille was annoying me the night that Will came over to after Benedict's party so I kissed him to make her jealous and persuaded Will that he imagined it, so Alec I never had any history with Will."

Alec's eyes softened. It was silent for a moment until Jace broke it "So Tessa, what is your story with shadowhunters."

Tessa looked at him before cautiously saying "Have you ever looked at your family tree?"

"Not really, since I only recently found out about my heritage."

"Well if you would be kind enough to show it to us you guys may be able to spot how I knew the Shadowhunters."

So Jace stood up and got the family tree. He spread it out and everyone except Magnus and Tessa circled around it. It was silent until Simon said "Tessa, you're on the tree."

"So you noticed." Stated Tessa tears brimming her eyes. The gears in Jack's mind were working overtime. Was Tessa his great, great, great grandma?

"It says you were married to William Herondale. So he was straight and never had anything with Magnus." Alec gleefully added.

"Yes, my life was especially intertwined with the Herondales'." Sniffed Tessa. Then the story poured out of her, she told them about Mortmain, Jem, Will, the automatons, Nate, her whole life in the 19th centaury. Everyone was quiet the whole time and yes even Jace. Jace was in full thinking mode throughout the whole story. Things like, so that is how I got my birthmark, Will had handsome looks too, DUCKS, how does she end up with Will when she was engaged with Jem?

When Tessa finished retelling her story it was quiet, until Jace asked "How does your shape shifting work? Can you show us?"

Tessa thought for a moment "Yes, I suppose I can. Can one of you guys give me something of yours, a ring or something, preferably Izzy."

"Why me?" Isabelle inquired.

"You and I are about the same size and build, so the outfit I am wearing now would probably fit you, but if I changed into Clary I am afraid the leggings would be much too long.

Accepting the answer Izzy nodded her head and gave her her ruby pendent. Tessa smiled saying "This used to belong to Will before he gave it to Cecily who passed it down her bloodline, and I am not mistaken it had belonged it Magnus before that."

Everyone looked at Magnus who explained "I bought it for Camille but gave it to Will because I got irritated with her."

Tessa held the pendant in her hands and closed her eyes and changed into Izzy. Her brown hair turned black and runes started to appeared on her skin. As she opened her eye they were brown instead of grey. Everyone gasped and Izzy screeched "No one told me that nose is so large!"

Tessa laughed "That is exactly what Jessamine said when I changed into her"

Jace knew warlocks that could shape shift, so what was so special about her. "So what is so special about your ability compared to other shape shifters?"

Tessa smiled and changed back while handing Izzy her pendent back. "I can fully become the person, meaning I have access to their memories.. For example do want to know what happened in Idris in Alec's bedroom between Izzy and Simon?" Izzy jumped up and tackled Tessa. She laughed "I was not going to tell them." Tessa looked at the clock on the wall and sighed, "Well, I must leave, Jem is going to get home soon. It was a pleasure meeting you all. Perhaps we'll meet again." Tessa got up and walked out of the library waving goodbye. Jace sat there and stared at the doorway that Tessa had just walked out. Did he really just meet his ancestor?

 **I hope that was not too bad... I don't have much to say other that so I guess, thanks for reading and feel free to review. Any type of advice would be greatly appreciated.**

 **-Mailani**


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